Pronged plug with rotatable core having cord insulation and conductor anchorage means



Nov. 18, 1952 2,618,679

W. H. COOK PRONGED PLUG WITH ROTATABLE CORE HAVING CORD INSULATION AND CONDUCTOR ANCHORAGE MEANS Filed April 18, 1949 Patented Nov. 18, 1952 UNITED STATES PATENT OFFICE PRONGED' PLUG" WITH ROTATABLE CORE HAVING CORD INSULATION AND CON- DUCTOR'ANCHORAGE MEANS William H. Cook, Toledo, Ohio Application April 18, 1949, Serial No. 88,089

6 Claims. 1

This invention relates to efiicient anchoring of insulation-covered electric conductors at electric terminals.

This invention has utility when incorporated in electric terminal carying fittings, more particularly of the prong type. Between aninsulation housing or shell and a relatively angularly shiftable plug seated therein to look a terminal or terminals, there is, for each conductor or leadin wire, a course along a multiple restriction way of the plug past terminal projections or fingers located in the way enlargements at the restrictions. Upon shifting of the plug relatively to the shell, the seat restrictions or interruptions and fingers oppositely coact. upon a coursedirected lead-in wire to kink-grip the insulation jacket or cover andcrimp the wire strands eiiectively holding the assembly in tight electric conductive relation.

Referring to the drawings:

Fig. 1 is a side elevation, with parts broken away, of an embodiment of the invention in a two-prong type of electric fitting:

Fig. 2 is an end elevation, or View looking from the line IIII at the left of- Fig. 1, showing the conductor lead entrance end of the fittting;

Fig. 31s anopposite end elevation from that of Fig. 2, being a view lookin from the line IIIIII, a portion of the plug and one terminal being broken away;

Fig. 4 is an upper half side elevation and lower half medial longitudinal section of the insulation plug housed by and angularly shiftable in the shell of the fittting unit of Fig. 1;

Fig. 5 is an end elevation looking from the line Fig. 6, and being adapted to have the unjacketed wire strands directed therethru;

Fig. 8 is a section on the line VIIl-VIII, Fig. 4, at the inner limit or end enlargement of the way, and of aproximately similar dimension to the enlargement shown inFig. '7, and in which 7 the stranded wire has its thrust-in limit along the course of the plug;

Fig. 9 is an opposite end elevation or from the line IX-IX, Fig. l, to that shown in Fig. 5, and showing the eoin-receiving-edge seat for plug 2 actuation, shown as 90 clockwise to gripping position from the showing in Fig. 3;

Fig. 10 is a side elevation of a terminal prong adapted to be seated in the insulation shell of Fig. 1;

Fig. 11 is an enlarged view in-section and perspective from the line X[XI, Fig. 10, showing a seat to be engaged by a spring lock strip;

Fig 12 is an enlarged view in perspective of terminal spring lock strip, adapted to anchor a prong with the shell;

Fig. 13 is a section on the line XIII-XIII, Fig. l, of jacketed stranded lead-in wires at the kink receiving entrance therefor;

Fig. 14 is a fragmentary view of a kinked and crimped lead-in wire as acted upon by the fitting of Fig. 1;

Fig. 15 is a largely broken away view of a different type of locking strip from that shown in Figs. 1, 12; and

Fig. 16 is a plan view of the strip of Fig. 15.

The housing A housing or shell I of insulation, has at its larger end 2 an opening 3 to a cylindrical chamber with diametrically dsposed channels or ways 5 therealong. Spaced from the end 2, each seat or way 5 has anarrow ledge or shoulder 5 to a slightly deeper portion '1. As an inner end to the way 5 there is a seat 8 providing clearance at two sides of a circular opening 9 in a wall having on its opposite side from the chamber 4, a wedge or V-guide or spreader rib It at the inner end of a. cylindrical throat II from smaller end I Zremote from the end 2. From the end 2 the housing or shell I'has major parallel sides I 3 connected by rounded corners Hi to minor parallel sides I5, which sides merge into a conicalportion I6 toward the end I2.

The plug Adapted to be seated in the chamber 4 and flush with the end 2, is an insulation plug having a head I? with diametricalribs I8 therefrom to a base I 9 having squeeze-efiecting sides 28 for receiving-way portions 2I initially in register with th housing wall'openings 9 as coin notch 22 in the plug head Ii lies parallel to the sides I5 in extending between the sides It or the housing i (Fig. 3).

An electric conductor lead-in is shown with an insulation covering or jacket 23 about stranded wires 24. End 25 of the insulation covering 23 in its thrusting thru the openings 9 as directed by the wedge I9, is thru the way portions 2i into clearance or enlargement 26 in the plug to a notch resriction 21 (Fig. 6). The less diameter stranded wires 24 pass on thru the restriction 21, across a first minor clearance or enlargement 28 to pass thru a restriction 29 (Fig. '7) into a second minor enlargement or clearance 39, for the wires 24 at their ends there to abut inner side 3! of the head I! of the plug.

The terminal The terminal is shown comprising a prong portion 32 having an inward offset 33, say approximating half its metal thickness, with a straight extension 34 adapted to extend along in a seat to an end fiange or finger 35 to register in the seat 8 in proximity to the opening 9 in the complementary or outer insulation section or housing Spaced from the finger 35 along the extension 34 of the terminal a distance slightly less than the thickness of the base l9 plus the length along the insulation plug of the clearance 25, is a second somewhat minor finger 35, integral with the extension 34. The position of this second finger 36 is such that in the clearance 26 it will ride not quite to the restriction 21, and thus be free upon angular shifting of the plug H in the housing l, to have the restriction 2! pinch the strands 24, while at the same time the wedge faces 25 are crowding the lead-in wire insulation covering 23 and acting in a shearing or transverse course as to the openings 9 in establishing an ogee-like kink 3'! (Fig. 14)

In proximity to the restriction 29 from the clearance 28 (Figs. 4, and in proximity to the wall 3| in the clearance 38, fingers 38, 39, integral with the terminal extension 34, coact somewhat progressively in a pitch line of say 10, and each with a slightly skew corner 40 the more firmly to bite against the stranded wire in efiecting further kinks 4| (Fig. 14). There may be sligth circumferential clearance for the plug as to the inner wall of the housing forming the chamber From the head 11, the plug may have a taper along the ribs [8 up to 5".

The lead-in gripping action is such that initial angular shifting of the plug as to the shell l, takes hold of the somewhat compressible insulation covering 23 as held by the opening 9 and the squeeze acts thru the seat sides 20 for the plug end l9 at the ways 2|.

This gripping action upon the lead-in conductor insulation is positive. Accordingly, it takes away all tension or pulling strains from being local to the wire strands. The transverse distortions or cross-wise twistings, acting upon the wire strands in the sequence by the fingers 36, 38, 39, in opposition to the restrictions 21, 29, establish first major pulling away from the wall 3| by the finger 26, with the fingers 38, 39, coacting as fol low-ups against rupturing the strands, while establishing electrical-conductor contact-maintaining relations for the strands with the terminal.

Terminal locking A bronze shim or spring metal strip 42 is provided with an ofiset claw 43 at its inner end 44. Remote from the end 44, the strip 42 has a pair of marginal spring arms 45, spaced by a considerably shorter oppositely deflected spring torque 46 (Fig. 12).

Before placing the terminals 32, 34, in the housing i, convenient assembly may be effected by locating the strips to have the claws 43 ride in a seat 41 (Fig. 11) at each finger 36. The terminals, as thus spaced by the plug, may be thrust thru the opening 3 into the chamber 4, to ride as to the terminals along the seats 5 for the tongues 45 to engage back of the shoulders 6. The spring action of the tongue 46 and of the arms 45, take up any lost motion or play clearance for the terminals between the insulation members I, IT. The terminals are thus positively locked against any shifting, and the ofisets 33 anchor the plug in the shell, with the plug relative movement confined to angular shifting, say in a range up to for locking lead-in conductors. Reverse turning of the plug may release the lead-in wires for replacement or substitution.

A marginally jagged strip 41' (Fig. 15) may be snagged with the sides of the way 5 against pullout, and an ofiset 48 from the strip 41 be lodged in a recess 49 (Fig. 15) in a terminal extension 34. This is an alternative terminal locking disclosure.

What is claimed and it is desired to secure by Letters Patent is:

1. An electric fitting including an insulation cylindrical plug having in lineal succession a series of circumferentially extending groove sections spaced by a plurality of ribs, an adjacent pair of said ribs having a notch of one aligned with a notch of the other to form parallel to the axis of the plug a way across the spacing groove between the ribs for insertion of a lead-in conductor.

2. An electric fitting comprising an insulation housing section having a chamber open at one side and a cord opening leading into said chamher, an insulation plug section relatively rotatable in said chamber, a terminal seated in said housing and connected to one of said sections and having a plurality of spaced laterally projecting fingers, a plurality of ribs on the other of said sections and relatively movable between said fingers, and a channel extending across said ribs and having an open end which in one position aligns with said cord opening, whereby the relative movement of said sections crimps a wire when inserted through said cord opening into said channel.

3. An electric fitting according to claim 2 wherein said plug section includes a slotted end exposed in the open side of said chamber, whereby said plug section may be rotated with respect to said housing section.

4. An electric fitting comprising an insulation housing section having a chamber open at one side and a cord opening leading into said chamher, an insulation plug section relatively shiftable in said chamber, and a terminal seated in said chamber and connected to one of said sections and having a plurality of spaced laterally projecting fingers, the other of said sections having a plurality of ribs relatively movable between said fingers, with a channel extending across said ribs, said channel having an open end which in one position aligns with said cord opening, whereby the relative movement of said sections crimps a wire when inserted through said cord opening into said chamber.

5. An electric fitting according to claim 4 wherein said terminal is connected to said housing section, and said ribs are on said plug section.

6. An electric fitting comprising an insulation housing section having a chamber open at one side and a pair of cord openings leading into said chamber, an insulation plug section relatively shiftable in said chamber, and a pair of terminals seated in said chamber adjacent said pair 5 6 of openings and connected to one of said sections, UNITED STATES PATENTS each terminal having a plurality of spaced later- Number Name Date ally projecting fingers, the other Of said 560- 449 04 Weller Mar 31 1 9 tions having a plurality of ribs relatively movab 1 309 887 Fulton Q I Jun 15 1919 between said fingers with a pair of channels ex- 5 1645650 Oct 1927 tending across said ribs, said channels each hav- 1953594 Douglas 1934 ing an open end which in one position of said 2o69375 Lane 1937 sections aligns with one of said cord openings, 2125555 Frantz 1933 whereby the relative movement of said sections 2157919 Reese 1939 crimps each wire of a pair when inserted through 10 2214024 1940 Said 00rd Openings into Said Channel 212291794 Brownstein 1:11-; Jan 28, 1941 WILLIAM H' COOK. 2,466,930 000k Apr. 12, 949 2,482,965 Cook Sept. 27, 1949 REFERENCES CITED 1 FOREIGN PATENTS The following references are of record in the 0 Number Country Date file of t Patenti 248,616 Switzerland Dec. 1, 1947 

